SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ccb58bf47728f22d2813b0269f8277d6a8e726b008b019cee406d70859a87be9' 
  AND token = 'cL0FJzIkjOxMQblPnv89miDEtQzZyw04GSap6MvOPvI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}